The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Zeiss Otus 100mm F1.4 and the Sigma 105mm F2.8 EX DG OS HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Zeiss Otus 100mm F1.4 is the longer of the two lenses at 129mm. The Sigma 105mm F2.8 EX DG OS HSM with a length of 127mm, is 2mm shorter. Besides being longer, the Zeiss Otus 100mm F1.4 also has a larger diameter of 101mm compared to the Sigma 105mm F2.8 EX DG OS HSM's 78mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sigma 105mm F2.8 EX DG OS HSM weighs 726g, 48% (679g) lighter than the Zeiss Otus 100mm F1.4's weight of 1405g.
Filter Threads
The Zeiss Otus 100mm F1.4 has a filter size of 86mm whereas the Sigma 105mm F2.8 EX DG OS HSM has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 86mm filters that we recommend you to consider for the Zeiss Otus 100mm F1.4:
And these are the 62mm filters that we recommend for the Sigma 105mm F2.8 EX DG OS HSM:
Lens Mounts
Both the Zeiss Otus 100mm F1.4 and the Sigma 105mm F2.8 EX DG OS HSM has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Zeiss Otus 100mm F1.4 is also available in Canon EF mount.
Sigma 105mm F2.8 EX DG OS HSM is also available in Canon EF and Sigma SA mounts.
Focal Range
Zeiss Otus 100mm F1.4 is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
150mm.
On the other hand, the Sigma 105mm F2.8 EX DG OS HSM is a prime lens with fixed focal lenght of 105mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 157.5mm.